The Nationals MP for Tamworth, Kevin Anderson, says he's still working to address supply concerns, as he prepares a Private Members Bill to legalise cannabis use for the terminally ill.

Mr Anderson won't announce a date for the Bill to be tabled, but says he expects it'll be before the end of the year.

There are around 20 parliamentary sitting days left this year.

Two proposed trials for the growth of cannabis for medicinal purposes, in Tasmania and Norfolk Island, have both fallen through.

Kevin Anderson says work to find a safe way to supply the drug continues.

"There's a number of options that we've put forward, currently my colleagues are looking at that," he said.

"It's been back and forward a few times and they've said "Have you thought about this have you thought about that? Lets refine it just a little bit," because what we're going to see, is if this Bill is passed, this will set the precedent for Australia."

Kevin Anderson says he doesn't want to present something that's not going to be successful.

"If I can continue to work on this Bill, [and] get it to a point where I present it to Parliament and it gets approved and passes, then I think that's a much better option rather than to say the date it will be tabled on the floor of Parliament," he said.

"The date becomes the issue, and not the content and the outcome of the Bill."